Effect of malnutrition and nutritional rehabilitation on growth and serum growth promoting activity in developing rats.

ABSTRACT

Malnourished pups were obtained by increasing litter size to 20 pups/dam VS 10 pups/dam in controls. Rehabilitation was started when the pups were 17 days old. The normalized growth rate (% body weight increase/day) of the malnourished pups was significantly lower than that of controls at 10-17 days of age. After starting ad libitum feeding, the normalized growth rate became the same as that of control when both groups were at 17-23 and 23-34 days of age. The body weight of the previously malnourished pups was still lower than that of controls at 34 days of age. Serum growth-promoting activity (GPA) in malnourished and control rat pups was determined by measuring the degree of stimulation of thymidine incorporation into lymphocytes treated with low dose of phytohemagglutinin (PHA). The serum GPA in malnourished pups was lower than that of controls at 17 days old. When malnourished pups were weaned onto laboratory chow ad libitum starting at 17 days, their serum GPA at 23 and 34 days of age was found to be similar to that of control pups of the same age. We conclude that immediate postnatal malnutrition is associated with reduction of serum GPA and reduced growth.